Segregation chamber for transfusion sets



July 22, 1958 R. c. BEACHAM SEGREGATION CHAMBER FOR TRANSFUSION SETSFiled April 25, 1955 IN VEN TOR. Poundiam? WL LM Irma/w)? United StatesPatent SEGREGATI ON FOR TRANSFUSION Robert C. Beachman, Richmond,Califi, assignor to Cutter Laboratories, Berkeley, Calif., a corporationof California Application April 25, 1955, Serial No. 503,684

2 Claims. (Cl. 128--214) This invention relates to transfusion sets andin general has for its object the provision of a segregation chamber forinclusion in said sets and by which air embolisms in patients receivingtransfusions can be avoided.

As is well known, intravenous solutions are administered from a flask orbottle through a section of flexible tubing connected at its free end toa hypodermic needle. Since air embolisms should of course be avoided,all air contained within the flexible tubing should be completelydisplaced with the solution to be administered prior to the insertion ofthe hypodermic needle into the patient. Up to the present, this hasentailed arather tedious and time consuming manipulation of the tubing.Furthermore, as the end of the administration approaches and thesolution has been substantially drained from its container, care againmust be taken to insure that no air becomes entrained in the solutionand which might thereby result in an embolism. In short, withtransfusion sets now commercially available there is danger of producingair embolisms both at the beginning as well as at the end of anadministration. Furthermore, the problem has been made more acute due totwo additional factors. Customarily a drip meter, oftentimes incombination with a filter, is inserted in the transfusion line, the dripmeter chamber being a site at which additional air can be entrained inthe intravenous solution. nous solutions are administered under pressureto give rapid transfusions. Although this pressure is not great,nevertheless it can be the cause of an increase in the amount of airentrained in the solution particularly at the site of the drip meter. p

More specifically then, it is the object of this invention to provide anair segregator in combination with a drip meter for insertion in theline of :a transfusion set, the segregator being provided adjacent itsbase with a guided float valve for permitting deaerated solution to passinto the'tubing leading to the injection needle and for closing off theoutlet port of the segregator upon the depletion of its solutioncontent.

The invention possesses other advantageous features, some of which, withthe foregoing, will be: set forth at length in the following descriptionwhere those forms of the invention which have been selected forillustration in the drawing accompanying and forming a part of thepresent specification, are outlined in full. In said drawing, threeforms of the invention are shown, but it is to be' understood that it isnot limited to such forms, since the invention as set-forth in theclaims may be embodied in other forms.

Referring to the drawings:

Fig. 1 is a side elevation of an air segregator embodying the objects ofmy invention, the lower half thereof being shown in mid-section thebetter to illustrate its construction and operation.

Fig. 2 is a vertical mid-section of a modified form of my invention. 1

Fig. 3 is a transverse section takenon the section line 3-3 of Fig'. 2.

Fig. 4 is a vertical mid-section of a further modification of myinvention.

Frequently intraveice Fig. '5 is a transverse section taken on thesection line 5-5 of Fig. 4.

As illustrated in Fig. 1, the-objects of my invention have been embodiedin a combination air segregator and drip meter comprising a transparentplastic cylindrical chamber 1 having an integrally formed top 2 and anintegrally formed hollow connection spike 3 terminating at its lower endin a drip nipple 4. Extending into and sealed to the lower counterboredend of the chamber 1 is a bottom cap 5 provided with an outwardlyextending marginal flange 6 overlying the lower end of the chamber andforming a labyrinth seal therewith. Depending from the cap 5 is anoutlet nipple 7 having a bore 8 merging at its upper end with acounterbore 9 defined by a boss 11 having an inclined marginal valveseat 12. Mounted in the counterbore 9 is an upstanding overflow nipple13 and which also serves as a float valve guide. Disposed over theoverflow nipple 13 is an inverted cup 14 formed of any suitable materialhaving a specific gravity somewhat less than the range of specificgravities of intravenous solutions in general use. The inner peripheralsurface of the lower end of the cup or float valve 14 is inclined so asto mate with the valve seat 12 and the height of the overflow guidenipple should of course be such as to permit the valve 14 to seat on itsvalve seat 12.

In the use of this device the connecting spike 3 is connected eitherdirectly with an intravenous solution bottle or indirectly therewiththrough a section 15 of flexible tubing. The outlet nipple 7 isconnected through a sec-' tion 16 of flexible tubing with a hypodermicneedle, this section of tubing being provided with a pinch valve. Thishaving been done the bottle is suspended in an inverted positionwhereupon solution flows into the air segregator. By then tipping thesegregator the valve closure cup 14 can be unseated whereupon airdisposed within its confines and above the solution level passes intothe nipple 13. As soon as sufiicient solution has flowed into thesegregator to float the cup 14, it can be uprighted. As this point thebottom of the cup will assume a level indicated by the dotted line 17somewhat below the upper end of the nipple 13, the level of the solutionbeing indicated by the line 18. In this positoin then, the cup serves toestablish a liquid seal between the mouth of the nipple 13 and thatportion of the segregator lying above the solution level. As a result ofthis liquid seal the further passage of solution through the segregatortakes place without the entrainment of air therein, and this in spite ofthe fact that air is contained within its upper portion and also withinthe upper end of the cup 14. As solution continues to pass through thenipple 13, nipple 7 and the tubing section 16, it will of coursedisplace any air contained therein. having been done, the operator orattendant can now proceed to make his injection.

When the bottle has been depleted of solution, the solution level in thesegregator will of course drop, thereby allowing the lower end of thecup to seat on the valve seat 12 thereby to preclude the further passageof solution to the tube section 16.

It will therefore be seen that I have provided a device for insertioninto a transfusion set whereby any air entrained in the system can bereadily displaced with solution, whereby the incorporation of air intothe solution during an administration is precluded and whereby the flowof solution through the tubing leading to the hypodermic needle is shutoff upon the depletion of the solution from the solution bottle.Furthermore, this device, has been incorporated in combination with adrip meter, the nipple 4 serving this purpose.

As illustrated in Figs. 4 and 5, the objects of my invention can also beembodied in a segregator comprising a cylindrical chamber 21 closed atits upper end and provided at its lower portion with a counterbore 22.Formed I This integral with the top 23 ofthe chamber is a downwardlydepending drip nipple 24 merging with an upwardly extending taperedspike 25 serving as an inlet to the chamber- 21. Closing the lower endof the chamber 21 is a bottom 26 having a labyrinth seal with thechamber 21in the same fashion as described with reference to themodification illustrated in Fig. 1. Depending from the bottom 26 is 'anoutlet nipple 27, the lower end of which is connected to a section 28 offlexible tubing provided at its free end with a hypodermic needle andadapted to be provided intermediate its ends with a pinch valve notshown. The upper end of the bore 29 of the nipple 27 is surrounded by anannular valve seat 31. Disposed within the lower end of the chamber 21is a cylindrical float closure member or valve 37 provided on its outerwalls with longitudinally extending ribs 33, these ribs having a freesliding fit with the inner diameter of the counterbore 22 and serving todefine passageways 34 for establishing communication between the freeend of the chamber 21 and its lower end. The lower face of the floatvalve 32 is arranged to seat on the annular valve seat 31 thereby toclose off the upper end of the bore 29. The upper end 35 of thecounterbore serves to limit the upward movement of the float valve 32.Extending through the upper portion of the chamber 21 is a vent hole 36for establishing communication between that portion of the chamber lyingabove the float and atmosphere.

In the use of this modification of my device the spike 25 is connectedeither directly to an intravenous solution bottle or indirectly theretothrough a section 37 of flexible tubing. This having been done, thesolution bottle is suspended in an inverted position thereby to permitsolution to flow through the tubing section 37 and through the dripnipple 24 into the chamber 21. The solution so delivered to the chamberpasses downwardly through the passageways or channels 34 to the lowerend of the chamber, thereby to float the float valve 32. Here it shouldbe noted that the cross-sectional area of the Dassageways or channels 34should be sufliciently small so that solution contained therein servesas an air seal. In other words, once these passageways have been filledwith solution, the solution contained therein will serve to block oflfthe further passage of air therethrough. When the float valve 32 hasbeen unseated, solution will be free to pass through the passageways 34from the upper end of the chamber into the nipple 27 and through thenipple and the tubing section 28 to the hypodermic needle. The initialportions of solution passing through the nipple 27 and tubing section 28will serve to displace all air entrained therein. Once all air has beenexcluded from these members the device is ready for the purpose ofmaking an intravenous injection for the air seal constituted by thesolution contained in the passageways 34 will thereafter preclude thefurther passage of air from the upper end of the chamber 21 to its lowerend. During the initial operation of the device, that is, during thetime that the float valve 32 is rising, a certain amount of air fromthat portion of the chamber above the valve 32 will escape through thevent 36.

It will therefore be seen that this modification like the modificationshown in Fig. 1 serves as a device for readily clearing the line ofentrained air prior to the administration of an intravenous injection,serves to avoid the entrainment of air with the solution during theadministration and serves to close the outlet of the segregation chamberwhen the intravenous solution bottle has been depleted of its contents.

In Figs. 2 and 3 the objects of my invention have been embodied in acylindrical chamber 41 closed at its upper end by a top 42 and having alabyrinth seal at its lower end with a bottom 43. Extending into the top42 is a drip nipple 44 merging with an upwardly extending tapered spike45 adapted to be connected either directly to an intravenous solutionbottle or indirectly thereto through a section 46 of flexible tubing..Formedat one side of the lower portion of the chamber 41 is acylindrical float guide 47 having a slot 48 on its inner side.

Formed integral with the bottom 43 in vertical registration with thecage 47 is a connecting nipple 49, the lower end of this nipple beingsecured to a section 51 of flexible tubing, the free end of which isarranged to be connected with a hypodermic needle. The upper end of thenipple 49 terminates in the valve seat 52 extending upwardly into thevalve cage-47. Disposed Within the valve cage 47 and freely' :slidabletherein is a hollow float valve 53 arranged in its lower position toseat on the seat 52, thereby to close off communication between the.chamber 41 and the nipple 49. Extending through the thickened side wallof the chamber 41 in vertical alignment with valve cage 47 is a venthole 54.

In the operation of this device, it is connected to an intravenoussolution flask in the same manner as above explained with reference tothe modifications described in Figs. 1, 4 and 5. When the intravenoussolution bottle is inverted, solution passes through the drip nipple 44to the lower end of the chamber and into the slot 48 of the valve cage.This serves to unseat the fioat valve 53 whereupon a certain amount ofaircontained within the chamber passes upwardly through the vent hole54. Simultaneously solution starts to pass downwardly through the nipple49 and its connected tubing section 51, this solution serving todisplace the air contents of these two members. When a solid column ofsolution has filled the nipple 49 and the tubing section 51, the deviceis ready for use in administering the solution. During theadministration of the solution, the flow of solution through the nipple44, drop by drop, is controlled by a pinch valve associated with thetubing section 51 and although air is contained within the chamber 41,no air is entrained with the solution passing downwardly through thenipple 49 during the administration procedure. When the contents of theintravenous solution bottle has been depleted and the level of thesolution within the chamber 41 drops, the float valve 53 likewise dropsto its seat 52, thereby precluding the further passage of solutionthrough the system and thus avoiding the entrainment of air with anyportion of the solution reaching the patient.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. An air segregator for transfusion sets comprising: a segregationchamber provided at its upper end with an inlet port and at its lowerend with an outlet port, said outlet port being circumscribed by a valveseat extending upwardly into said chamber; an inverted cup disposed insaid chamber in vertical alignment with said outlet port; and meanswithin said chamber for constraining said cup to move into registrationwith said valve seat upon the downward movement of said cup.

2. An air segregator for transfusion sets comprising: a segregationchamber provided at its upper end with an inlet port and at its lowerend with an outlet port, said 3 outlet port being circumscribed by aninclined valve seat extending upwardly into said chamber; an invertedcup disposed in said chamber in vertical alignment with said outletport; and means within said chamber for constraining said cup to moveinto registration with said .valve seat upon the downward movement ofsaid cup, the lower peripheral edge of said cup being tapered to matewith said valve seat.

References Cited in the file ofthis patent UNITED 'STATES PATENTS1,788,280 Dempsey Jan. 6, 1931 2,693,801 Foreman Nov. 9, 1954 2,729,212Butler Jan. 3, 1956 2,784,733 Martinez Mar. 12, 1957 FOREIGN PATENTS11,074 Germany Sept. 28, 1880

